1. Field of the Invention
The present invention relates to an inspection machine by compression for ceramic samples, and in particular, for ceramic samples having honeycomb structures.
2. Description of Related Art
Inspections by compression on a ceramic structure, such as a honeycomb structure, is performed by applying hydrostatic pressure on the ceramic structure. FIG. 4 is a perspective view of a conventional inspection method by compression having a configuration in which a sample 1, disposed in a urethane rubber cylinder 2 having an internal diameter corresponding to the diameter of the sample 1 and having a thickness of 1 to 2 mm, is provided with disk-like acrylic plates 3 attached to the sample 1 at the ends thereof, the acrylic plates 3 are fixed to the urethane rubber cylinder 2 by elastic bands 4, and the sample 1 covered by the urethane rubber cylinder 2 and the acrylic plates 3 is placed in water in a tank 5, whereby pressure is applied to the sample 1.
However, a problem in the above-described conventional inspection method by compression has been found to be that the efficiency of operation decreases when many samples are inspected because it is time-consuming to fix the acrylic plates 3 to the urethane rubber cylinders 2 by the elastic bands 4. Another problem is that it is difficult to clean the inspection device after inspecting when wet fractions of samples, which have been broken by the pressure, adhere to the urethane rubber cylinders.
In order to overcome these problems, an inspection machine by compression is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 10-197429, in which the inspection machine is provided with a cylindrical container, a urethane sleeve, and a urethane sheet. Inspecting using this inspection machine by compression is performed as follows. Referring to FIG. 5, a sample 1 provided with a urethane sleeve 7 around the same is placed in a cylindrical container 8 with a urethane sheet 9 disposed between the urethane sleeve 7 and the cylindrical container 8. A hydrostatic-pressure-applying medium is injected between the cylindrical container 8 and the urethane sheet 9, thereby compressing the sample 1 at the periphery thereof, whereby the inspection by compression is performed.
In this inspection machine by compression, the sample 1 is not fixed by elastic bands. Therefore, the efficiency of operation is not decreased when many samples are processed. Moreover, after inspecting, dry fractions of the sample 1 remain in the urethane sleeve 7. Therefore, cleaning of the inspection machine is easier than when using the urethane rubber cylinder 2 shown in FIG. 4.
However, a problem in the inspection machine by compression 1 shown in FIG. 5 is that it is difficult to control the pressure applied to the sample 1, because the compression of the sample 1 does not properly respond to the pressure applied to the pressure-applying medium due to the elasticity of the urethane sleeve 7.
Another problem is that it is difficult to apply a low pressure of not greater than 10 kg/cm2 to the sample 1 due to the elasticity of the urethane sleeve 7. That is, when the pressure on the sample 1 is desired to be at a pressure of 10 kg/cm2 or less, the pressure applied to the pressure-applying medium serves only to compress the urethane sleeve 7 and does not compress the sample 1.
Yet another problem has been found in the inspection machine by compression 1 shown in FIG. 5, in that a tact time of the test must be set to be long when a high pressure is applied to the sample 1, because there is a time lag before a pressure-load reaches the sample 1 after the pressure is applied to the inspection machine, the time lag being caused by the elasticity of the urethane sleeve 7, thereby reducing the efficiency in the operation. Furthermore, when a high pressure-load is applied in a short time, there is a risk of breaking the sample 1 by the shock of the pressure. Generally, when a lot of samples are inspected at high pressures, tact time required per sample for the inspection must be reduced so as to increase the efficiency of the inspection.
In the inspection machine by compression 1 shown in FIG. 5, the preparations for the inspection are laborious, in which each sample must be inserted to the urethane sleeve 7, then must be disposed in the cylindrical container 8. An easy method for cleaning the fractions of the sample 1 is also necessary.
Accordingly, it is an object of the present invention to provide an inspection machine by compression in which inspection operation and cleaning of the inspection machine are easy, application of a low pressure is possible, and a tact time required per sample for the inspection is reduced, thereby increasing the efficiency of the inspection.
To these ends, an inspection machine by compression for inspecting a ceramic sample is provided, in which the ceramic sample covered by an elastic sleeve disposed at the periphery of the sample is received in a cylindrical container across an elastic sheet provided between the cylindrical container and the elastic sleeve, and the ceramic sample is compressed by a hydrostatic-pressure-applying medium injected between the cylindrical container and the elastic sheet. The sample is received in an inspecting container provided with the cylindrical container including the elastic sleeve and the elastic sheet between the elastic sleeve and an inner wall of the cylindrical container.
In the inspection machine by compression according to the invention, the elastic sleeve is preferably brought into contact with the sample by high-speed-pressurizing, and may be compressed so as to apply pressure to the sample by low-speed-pressurizing. In the inspection machine by compression, the beginning of fracture of the sample is preferably determined by detecting fracture sound from the sample, thereby suspending pressurization.
In the inspection machine by compression according to the invention, the sample may have a honeycomb structure. The elastic sheet and the elastic sleeve may be made of urethane.